what's a good recieve pre amp? the Dosy or the Maco.

(avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


It's amazing the things people buy just to hear CB'ers better.

Sc

Slow Code wrote:
(avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


It's amazing the things people buy just to hear CB'ers better.

Sc

The real problem is that the pre-amps don't accomplish anything. They
are just a gimmick since they are unable to improve the signal-to-noise
ratio. All they do is boost everything... noise and all... LOL

www.telstar-electronics.com

On a sunny day (4 Sep 2006 16:51:16 -0700) it happened "Telstar Electronics"
wrote in
. com:


Slow Code wrote:
(avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


It's amazing the things people buy just to hear CB'ers better.

Sc

The real problem is that the pre-amps don't accomplish anything. They
are just a gimmick since they are unable to improve the signal-to-noise
ratio. All they do is boost everything... noise and all... LOL

www.telstar-electronics.com

This is actually not correct.
A good pre-amp would have bit better s/n ratio then the set it is used
with.
I have experiemented a lot in the long ago past with different configurations
for pre-amps, like transistor, MOSFET, FET, cascode etc...
Best I could come up with was 2 junction FETS in cascode.....
Maybe these days there are better solutions.
But I received the world on a little wire with SSB.
So, your next project: A good low S/N ratio pre-amp?
Probably not.
Maybe you were using your power amp as pre-amp?

"Telstar Electronics" wrote in message
ups.com...

Slow Code wrote:
(avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


It's amazing the things people buy just to hear CB'ers better.

Sc

The real problem is that the pre-amps don't accomplish anything. They
are just a gimmick since they are unable to improve the signal-to-noise
ratio. All they do is boost everything... noise and all... LOL



They seem to work fine for FM reception. I can get St.Louis radio stations
with the one I have hooked to the rooftop ant.
I'm not sure about results with AM/SSB CB, except I have worked weak
stations at night with no background noise and it made plenty of difference.
With a lot of background noise most cheap preamps increase the noise along
with the signal. A unit with some selectivity as to what you can filter out
of the amplified signal would be ideal, but probably not monetarily
feasible.

--
Suffer, unto me.
Indulge, my every need.
UV Count 1
Religion is a whore! (Slayer)

Jan Panteltje wrote:
On a sunny day (4 Sep 2006 16:51:16 -0700) it happened "Telstar Electronics"
wrote in
. com:


Slow Code wrote:
(avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


It's amazing the things people buy just to hear CB'ers better.

Sc

The real problem is that the pre-amps don't accomplish anything. They
are just a gimmick since they are unable to improve the signal-to-noise
ratio. All they do is boost everything... noise and all... LOL

www.telstar-electronics.com

This is actually not correct.
A good pre-amp would have bit better s/n ratio then the set it is used
with.
I have experiemented a lot in the long ago past with different configurations
for pre-amps, like transistor, MOSFET, FET, cascode etc...
Best I could come up with was 2 junction FETS in cascode.....
Maybe these days there are better solutions.
But I received the world on a little wire with SSB.
So, your next project: A good low S/N ratio pre-amp?
Probably not.
Maybe you were using your power amp as pre-amp?

Don't think a pre-amp like that is worth anything without some type of
additional circuitry to discern noise from signal... and that's not
easy to do. All you're doing there is compensating for a poor receiver.

www.telstar-electronics.com

On Mon, 4 Sep 2006 15:10:53 -0700, (avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


The Antron.

Brian is absolutely correct, a receive preamp won't accomplish much of
anything unless your radio's front end is messed up, or you are using
it with a low-tech or homebrew receiver.

The best way to improve signal-to-noise ratio is to use a better
antenna. As an added bonus, it will also improve your transmit range.

On a sunny day (5 Sep 2006 16:24:13 -0700) it happened "Telstar Electronics"
wrote in
. com:


Jan Panteltje wrote:
On a sunny day (4 Sep 2006 16:51:16 -0700) it happened "Telstar Electronics"
wrote in
. com:


Slow Code wrote:
(avj 1) wrote in
:

what's a good recieve pre amp? the Dosy or the Maco.


It's amazing the things people buy just to hear CB'ers better.

Sc

The real problem is that the pre-amps don't accomplish anything. They
are just a gimmick since they are unable to improve the signal-to-noise
ratio. All they do is boost everything... noise and all... LOL

www.telstar-electronics.com

This is actually not correct.
A good pre-amp would have bit better s/n ratio then the set it is used
with.
I have experiemented a lot in the long ago past with different configurations
for pre-amps, like transistor, MOSFET, FET, cascode etc...
Best I could come up with was 2 junction FETS in cascode.....
Maybe these days there are better solutions.
But I received the world on a little wire with SSB.
So, your next project: A good low S/N ratio pre-amp?
Probably not.
Maybe you were using your power amp as pre-amp?

Don't think a pre-amp like that is worth anything without some type of
additional circuitry to discern noise from signal... and that's not
easy to do. All you're doing there is compensating for a poor receiver.

Well, the purpose of a pre-amp _______ I S _______ fixing a poor receiver.
If your receiver already has a top noise figure, and the pre-amp the same,
it will not help , see what I wrote above:
self quote
A good pre-amp would have bit better s/n ratio then the set it is used with.
end self quote

If you are sucked up in the ignition noise of your hair dryer or whatever,
then it will not help either.
Ad Dr Death already pointed out, it DOES help if the band is sort of clean.

I had all stages tunable, (tried both with varicaps and real rotary caps),
you need a high Q (I used heavy silver plated coils), very good antenna
matching, so you get maximum input signal (I used an input transformer),
and lowest noise figure FETS or whatever you can get.
The cost is practically nothing (maybe less then 50$ parts).
There are some more tricks like feedback you can use to get better Q.
You only need 3.5kHz bandwidth at 27MHz for SSB, and, as B = f0 / Q, a
Q of 27000000 / 3500 = 7714 should be the limit.
Not easy to get there !, but with feedback.......
Tuning it becomes a problem.... lots of knobs....
Did not use _that_ much feedback, basically keep the loading on the input
LC minimal.

A next project for you?
That was 1970 ties. What one could do with modern tech.

Frank Gilliland wrote:
Brian is absolutely correct, a receive preamp won't accomplish much of
anything unless your radio's front end is messed up, or you are using
it with a low-tech or homebrew receiver.

Right on... that's why I don't include that gimmick in any of my
amplifier designs.

www.telstar-electronics.com

On Mon, 04 Sep 2006 23:15:05 GMT, Slow Code wrote:

(avj 1) wrote in
:
+++
+++ what's a good recieve pre amp? the Dosy or the Maco.
+++
+++
+++It's amazing the things people buy just to hear CB'ers better.
+++
+++Sc
****************

Things people buy to better hear noise!


james